Assessing the Host Range of Ophraella communa for the Biological Control of Ambrosia artemisiifolia in France

<i>Ambrosia artemisiifolia</i> is a well-known invasive species in Europe, causing health issues with its extremely allergenic pollen and yield loss through competition in agriculture. One potential biological control agent is <i>Ophraella communa</i>, accidentally introduced in Europe in 2013. This species was discovered in France in 2023, but before planning further mass releases for biological control, it is necessary to assess its safety for agricultural crops and local plant biodiversity. Prior to its first detection in France, we conducted a host-range study of the beetle in a confined laboratory with no-choice and choice tests for 16 plant species, selected based on the centrifugal phylogenetic method. Results showed a restricted host range to the Heliantheae tribe and minimal risk to indigenous European plant species, with no larval survival and barely any eggs laid on these plants. Choice tests also showed a strong preference of <i>O. communa</i> for <i>A. artemisiifolia</i>. Our results combined with previous studies and observations in the field in other countries suggest a low risk to sunflower, <i>Helianthus annuus</i>, which is an important crop in France. This confirms that <i>O. communa</i> could be a low-risk biological control agent that can be used in classical biological control programs against <i>A. artemisiifolia</i> in France.